1. Field of the Invention
The invention relates to a multilayer aligned-winding coil which is formed by winding, in alignment, a wire of wide width in the form of a multilayer tube.
The “wire of wide width” is referred to, herein, as a wire having a width greater than a thickness and having a region of substantially constant thickness at a widthwise central region thereof. The term “tubular” or “tube” for the multilayer aligned-winding coil is referred to as the coil being in the form or shape of a tube. There may be or may not be a core body inside the tube. When the coil has the core body, the core body may be solid or hollow. The “aligned-winding” of the multilayer aligned-winding coil having a plurality of rows of winding portions, is referred to as a winding where adjacent rows, among majority of rows of said plurality of rows, of winding portions are wound to be arranged substantially in parallel and substantially in close or approximate contact with each other at mutually opposed or faced side edges thereof. More specifically, in a case where the wire of wide width is wound at the same layer as a previously wound portion as the winding of the coil, the “aligned-winding” is referred to as the wire of wide width being wound in alignment with the adjacent winding by being wound on the lower winding layer (or on an outer periphery of the winding core in case of the lowermost layer) with a side edge thereof forced to an adjacent side edge of the lastly wound winding portion so as to follow substantially the lastly wound winding portion or as the coil thus wound. In a case where the wire of wide width forms the first turn of each layer of the coil, “aligned-winding” is referred to as the wire of wide width being wound on the lower winding layer (or on an outer periphery of the winding core in case of the lowermost layer) with a side edge thereof forced to an adjacent support face of a flange so as to follow the support surface or as the coil thus wound.
2. Description of the Related Arts
Conventionally typical example of multilayer aligned-winding coils are two kinds of multilayer aligned coding coil of rectangular wire, i.e., wire having rectangular cross-section, having been developed by the present inventor and was disclosed with illustrations in Japanese Patent Publication No. 2001-196238(A) referred to hereinafter as a patent document 1.
The most typical coil of two kinds is a type of the coil disclosed in FIGS. 1 to 3 of the patent document 1 and has a structure shown in attached drawings FIGS. 17A, 17B and 17C.
In the conventionally typical rectangular wire multilayer aligned-winding coil 101, as shown in FIGS. 17A, 17B and 17C, winding parts at three sides PS1, PS2, PS3 of the coil 101 having a cross-section PV (cross-section perpendicular to the central axis PC1 extending in the longitudinal direction of the coil 101) in the shape of rectangle PS comprise transverse winding parts PY1, PY2, PY3 (shown by reference symbol “PY1” when plural transverse winding parts of the first layer are not distinguished, and further shown by reference symbol “PY” when layers are not distinguished) extending along the cross-section of the multilayer aligned-winding coil 101, and a winding part at the remaining one side PS4 of the rectangle PS comprises an obliquely crossing winding part PR1 (shown by reference symbol “PR” when the layers are not distinguished) extending obliquely with respect to the cross-section to shift by one wire PD1. In this multilayer aligned-winding coil 101, transverse winding parts PY1 are arranged substantially in close contact with each other, and the length of the coil 101 is substantially integral multiple (5 times in the illustrated case) of the width of the transverse winding part PY. In this multilayer aligned-winding coil 101, turning points PT1, PT3 between the obliquely crossing winding part PR1 and the transverse winding parts PY1, PY3 are formed at corners PK1, PK4. As shown in FIG. 17B, a transverse winding part PY2 progressively ride on an obliquely crossing winding part PR1F at the last row of the first layer PL1 of the multilayer aligned-winding coil 101. Thus, a progressively riding part PZ is formed, where the progressively riding part PZ is situated at a region, of the side PS4, close to the corner PK4. As shown in FIG. 17C, the second layer PL2 of obliquely crossing winding part PR2 includes a first row of obliquely crossing winding part PR21 extending to follow side edges, at the second row side, of the progressively riding part PZ and consecutive transverse winding part PY21. In this case, the obliquely crossing winding part PR21 of the second layer is situated at a side PS3 which is more upstream-side by one than the obliquely crossing winding part PR1 of the first layer in view of the winding direction of the wire. The aligned-winding of the second layer is made in the same way as the winding of the first layer except the above-mentioned point. The winding of the third and further layers are made in the same way.
In this type of rectangular wire multilayer aligned-winding coil 101, as seen from FIG. 17C, for example, on the side PS3 where an obliquely crossing winding part PR21 at the first row of the second layer and a transverse winding part PY12F at the last row of the first layer situated thereunder are partially superposed, a gap PG1 is produced. The gap PG1 is relatively large (having a volume of about a half of that of a transverse winding part PR2), and therefore the space factor of the multilayer aligned-winding coil 101 is reduced by the amount corresponding to the volume of the gap PG1. The gap PG1 is produced at every region between the layers. The reduction in the space factor becomes conspicuous when the multilayer aligned-winding coil 101 has many layers. In particular, as the number of rows of windings constituting the multilayer aligned-winding coil 101 becomes smaller, the reduction in the space factor becomes larger and not negligible.
Another type of multilayer aligned-winding coil the inventor proposed in the patent document 1 is disclosed in FIG. 10 of the patent document 1 and has a structure shown in the attached drawings FIGS. 18A, 18B and 18C.
This second type of multilayer aligned-winding coil 201 is, as shown in FIGS. 18A, 18B and 18C, the same as the multilayer aligned-winding coil 101 of FIGS. 17A to 17C on the point that the wire PD1 of wide width such as the rectangular wire is wound in alignment in the form of a multilayer hollow rectangular cylinder 202 and on the point that each layer PL has an obliquely crossing winding part PR extending in an oblique direction PB1 with respect to the cross-section PV (virtual plane substantially perpendicular to the longitudinal axis PC1 of the tube) of the tube at one continuous angular region PS4 (one side of four sides PS1, PS2, PS3, PS4 constituting the rectangle PS in this case) of virtual endless ring PS (rectangle in this case) defined by the cross-section of the tube 202, and transverse winding parts PY11, PY12, PY13 extending in the transverse direction PF along the cross-section PV at remaining angular regions PS1, PS2, PS3 of the endless ring PS.
However, in the second multilayer aligned-winding coil 201, as seen from FIG. 18A, the length of the coil 201 is longer than the integral multiple (5 times in the illustrated case) of the width of each of the transverse winding parts PY arranged in substantially close contact with each other by a width of a gap PG2 (the width of the gap PG2 is fairly smaller than the width of the rectangular wire PD1), and plurality of pairs of two consecutively superposed layers PLa, PLb meeting the following two conditions (1) and (2) are provided.
Condition (1)
As shown in FIG. 18B, provision of the first row of winding portion PW1 in the form of first transverse winding part PYA including a progressively riding transverse winding part PYM which ride progressively on the last low of obliquely crossing winding part PRF at a lower layer PLa of two layers PLa, PLb to reach from the lower layer PLa to an upper layer PLb thereover by one layer.
Condition (2)
As shown in FIG. 18C, provision of the second row of winding portion PW2 including a riding and obliquely crossing winding part or progressively riding and obliquely crossing winding part PRM extending to obliquely cross from a riding start region, of the progressively riding traverse winding part PYM of the first transverse winding part PYA, where the riding thereof on the obliquely crossing winding part PRF is started across a progressive riding region superposing at least partially on the obliquely crossing winding part PRF, and descending down at an extended end on the obliquely crossing winding part PR of the lower layer PLa, and
a second transverse winding part PYB turning at a turning point PTC at the extended end of the riding and obliquely crossing winding part PRM to extend along a side edge PE2, at a side of the second row, of the first row of transverse winding part PYA in said transverse direction PF.
In the second type of rectangular wire multilayer aligned-winding coil 201, the third layer PL3 (not shown) of winding wire is wound on the second layer PL2 of wire in the same way as the second layer PL2 of winding wire is wound on the first layer PL1 of wire, and the fourth layer PL4 (not shown) of winding wire is wound on the third layer PL3 (not shown) of wire in the same way as the third layer PL3 (not shown) of winding wire is wound on the second layer PL2 of wire, and such superposition of layers are repeated.
More specifically, the riding and obliquely crossing winding parts PRM at the second rows of winding portions PW2 of at least two pairs of said two layers PLa, PLb among the plural pairs of said two layers have ride-over region parts PX, obliquely riding over the progressively riding regions of the progressively riding traverse winding parts PYM, constantly at the same angular region (region of the side PS4 adjacent to the corner PK1 in the illustrated case) in terms of the angular region of the endless ring PS defined by the cross-section of the tube.
In the type of multilayer aligned-winding coil 201, as seen from FIG. 18C, a gap PG3 at the side PS4 where the first row of obliquely crossing winding part PRM at the second layer PLb superposes on the transverse winding part PYA at the last row of the first layer PLa is smaller than the gap PG1 of the first type of multilayer aligned-winding coil 101, which enhances, by the differences of the gaps (even though the volume of the small gap PG2 is also taken into consideration), the space factor of the multilayer aligned-winding coil 201.
However, the inventor has found it unavoidable that a protrusion PH is formed upstream of turning point PTC in this type of multilayer aligned-winding coil 201, and has further found, after detailed study of the state of the winding wire PD1 of the multilayer aligned-winding coil 201, the followings.
In the multilayer aligned-winding coil 201, a part, of the progressively riding transverse winding part PYM, where the riding and obliquely crossing winding part PRM completes the oblique crossing has approached to the upper layer Lb by the advancement of progressive riding. Therefore, the ride-over region PX, of the riding and obliquely crossing winding part PRM, before descending down from the progressively riding transverse winding part PYM reaches at a position (substantially the third layer when the upper layer is the second layer) fairly higher than the upper layer Lb. More specifically, the ride-over region PX, of the riding and obliquely crossing part PRM, superposing the progressively riding transverse winding part PYM riding on the obliquely crossing winding part PR reaches a position fairly higher than the second layer. On the other hand, a part, of the riding and obliquely crossing winding part PRM, having descended onto the lower layer La is situated at a position just as high as the upper layer La. Therefore, in the ride-over region PX before the turning point PTC between the riding and obliquely crossing winding part PRM and the second transverse winding part PYB, the protrusion PH protruding in an outward direction PJ is formed at and near the corner PK1 of the rectangle or square PS in view of the cross-section PV.
This type of protrusion or projection PH, at the ride-over region PX where the riding and obliquely crossing winding part PRM crosses over across the progressively riding transverse winding part PYM progressively riding the obliquely crossing winding part PR, is unavoidably formed by the superposition of three associated winding parts, and therefore the protrusion PH is formed at any two adjacent layers under thus-described the relationship or conditions.
Therefore, when the superposition of layers are repeated, protrusions PH are formed at substantially the same position in view of the cross-section of the multilayer aligned-winding coil 201. When these protrusions PH are superposed, the magnitude of protrusion becomes larger, which substantially disables or prevents the aligned-winding of wires PD1.
The inventor further improved the second type of multilayer aligned-winding coil and developed an improved rectangular wire multilayer aligned-winding coil and produces and sells the improved rectangular wire multilayer aligned-winding coil. The improved rectangular wire multilayer aligned-winding coil 301 and an outline of the way of winding thereof are shown in FIGS. 19A, 19B, 19C, 19D, 19E, 19F, 19G and 19H. The coil 301 is described in the “Related Art” because the coil 301 itself has been sold as a product and has been used. However, the process or method, per se, of winding the coil 301 is not known to public.
The multilayer aligned-winding coil 301 has, as seen from drawings such as FIGS. 19A and 19B, an obliquely crossing winding part PR at a partial angular region θ1 of one side PS1 of the four sides PS1, PS2, PS3 and PS4 constituting the rectangle or square PS. In the following, multilayer aligned-winding coil is illustrated as each layer thereof having four rows so that the problems in the multilayer aligned coil having been produced and sold can be clearly understood. In addition, each part of the multilayer aligned-winding coil 301 is shown by L(i; j; k) where i=1, 2, 3 or 4; j=1, 2, 3 or 4, k=1, 2, 3 or 4. In this expression, “i” denotes a layer. For example, i=1 corresponds to the first layer (lowermost or lowest layer). Similarly, “j” denotes a row. For example, j=1 corresponds to the first row, which is the right end row for the odd number layer and the left end row for the even number layer. Further, “k” denotes four sides. For example, k=1 corresponds to the first side.
More specifically, as seen from drawings such as FIG. 19A showing the start of winding, FIG. 19B showing a state where the winding of the 3rd turn has been completed, and FIG. 19E showing a state where the winding of the 7th turn has been completed, the multilayer aligned-winding coil 301 has an obliquely crossing winding part PR at a partial angular region θ1 of a winding part L(i; j; 1) constituting a side S1 and a transverse winding part PY at a remaining angular region θ2 of the winding part L(i; j; 1) constituting the side S1. Each of the winding part L(i; j; 2), L(i; j; 3) and L(i; j; 4) each constituting a respective side PS2, PS3 or PS4, consists only of the transverse winding part PY. FIGS. 19C, 19D, 19F, 19G and 19H show respectively the states where 4th turn, 5th turn, 8th turn, 12th turn and 13th turn have been completed and the subsequent turns of winding have been started.
The winding part L(i; 4; k) at the last row of each layer has a form or configuration different from the winding part L(i; m; k) (where m=2, 3) at the other rows of the layer. Similarly, the winding part L(i+1; 1; k) at the first row of an upper layer, i.e. a layer just above the layer, has a form or configuration different from the winding part L(i+1; m; k) (where m=2, 3) at the other rows of the upper layer.
The last winding part L(1; 4; 1) at the fourth row of the first layer, i.e. the last winding part Q1f of the fourth turn of wire, as seen from FIG. 19C and FIG. 20A showing an enlarged view thereof, takes not a form of an obliquely crossing winding part PR but a form of a progressively riding transverse winding part PYM1 progressively riding on an obliquely crossing winding part PR situated at the region from the last of the third row L(1; 3; 1) of the first layer to the first of the fourth row L(1; 4; 1). The first winding part at the first row L(2; 1; k) of the second layer, i.e. the first winding part Q2s of the 5th turn, typically just rides on the transverse winding part PY which is the first winding part at the fourth row L(1; 4; 1) of the first layer, and is the same as other parts.
The last winding part at the first row L(2; 1; 1) of the second layer, i.e. the last winding part of the 5th turn, as seen from FIG. 19D and FIG. 20B showing an enlarged view thereof, has a ride-over region part PX2 obliquely crossing from the riding start region, where the riding of the progressively riding transverse winding part PYM1 on the obliquely crossing winding part PR is started, across the progressively riding region, of the progressively riding transverse winding part PYM1, which is partially superposed on the obliquely crossing winding part PR. The last winding part takes a form of a riding and obliquely crossing winding part or progressively riding and obliquely crossing winding part PRM1 which descends on the first layer of obliquely crossing winding part at an extended end thereof where the last winding part is turned to follow the shape of the side edge PE2 at the first winding part of the first row of the second layer, on the first layer of obliquely crossing winding parts, to form the first winding part at the second row of second layer.
In the multilayer aligned-winding coil 301, the ride-over region part PX2, of the riding and obliquely crossing winding part PRM1, just before completing the oblique crossing over the progressively riding transverse winding part PYM1 is situated at substantially the third layer because of progress of the progressive riding. More specifically, the ride-over region PX2, of the riding and obliquely crossing winding part PRM1, superposing on the progressively riding transverse winding part PYM riding on the obliquely crossing winding part PR reaches at a position much higher (outer) than the second layer. On the other hand, a site or part, of the riding and obliquely crossing part PRM1, having descended on the lower layer PL1 is situated just at the second layer PL2. Therefore, a protrusion PH2 is formed to protrude outwardly PJ of the rectangle PS in the cross-section PV at the ride-over region PX2 before the turning point PTC2 between the riding and obliquely crossing winding part PRM1 and the second row of transverse winding part PY. As shown in the side view of FIG. 21A, it is unavoidable that the region PX2 before the turning point PTC2 more or less protrudes, as the protrusion PH2, in the outward direction PJ of the rectangle PS. The FIG. 21B is an oblique view similar to FIG. 20B.
Similar protrusion is produced for example at a region between the last winding part at the first row (9th turn) of third layer and the first winding part at the second row (10th turn) of the layer. However, this protrusion is situated at a region near an opposite end in the longitudinal direction of the coil 301.
Further, as seen from FIGS. 19G and 19H as well as FIGS. 22A and 22B showing the enlarged views thereof, similar phenomenon occurs at a region between the last winding part at the first row (13th turn) of the fourth layer and the first winding part at the second row (14th turn) of the layer.
More specifically, the last winding part Q3f at the fourth row L(3; 4; 1) of the third layer or at the 12th turn, as seen from FIG. 19G and FIG. 22A, takes not the form of the obliquely crossing winding part PR but the form of the progressively riding transverse winding part PYM3 progressively riding on the obliquely crossing winding part situated between the last region at the third row L(3; 3; 1) of the third layer and the first region at the fourth row of the layer. In addition, the last winding part at the first row L(4; 1; 1) of the fourth layer, i.e. the last winding part of the 13th turn, as seen from FIG. 19H and FIG. 23B, takes a form of a riding and obliquely crossing winding part PRM3, having a ride-over region part PX4 obliquely crossing over the progressively riding transverse winding part PYM3 from a riding start region thereof starting to ride on the obliquely crossing winding part PR across a progressively riding region thereof partially superposing on the obliquely crossing part PR, and descending on the third layer of obliquely crossing winding part at an extended end thereof. Further, the last winding part turns, at the extended end, to follow a side edge PE4 of the first winding part at the first row of fourth layer and to form the first winding part at the second row of the fourth layer.
Similarly, the ride-over region PX4, of the riding and obliquely crossing winding part PRM3, which is situated just before a position where the part PRM3 completes the oblique crossing over the progressively riding transverse winding part PYM3, proceeds to ride on to reach substantially as high as fifth layer. More specifically, the ride-over region PX4, of the riding and obliquely crossing winding part PRM3, superposing on the progressively riding transverse winding part PYM3 riding on the obliquely crossing winding part PR is situated higher than the fourth layer and reaches substantially as high as fifth layer. On the other hand, a site, of the riding and obliquely crossing winding part PRM3, having descended on the lower layer PL3 is situated at the fourth layer. Therefore, a protrusion PH protruding in the outward direction PJ in view of the cross-section PV is produced at the ride-over region PX4. As shown in the side view of FIG. 23A, an outer surface protrudes outwardly PJ as the protrusion PH4.
The ride-over region PX4 having the protrusion PH4 of the fourth layer is substantially superposed just on the ride-over region PX2 having the protrusion PH2 of the second layer. As a result, ride-over region PX4 protrudes further significantly in the outward direction PJ of the rectangle PS due to the overlapping of the region PX4 on the region PX2.
Therefore, the deviation of the multilayer aligned-winding coil from the rectangle PS becomes more larger. The deviation or distortion due to the protrusion becomes larger as number of layers in the multilayer aligned-winding coil 301 becomes larger, which may leads to a result that the wire of coil 301 cannot be wound in an aligned manner. Alternatively the space factor may be reduced due to reduction in the density of the winding wire or the predetermined turn of multilayer aligned-winding coil cannot be produced to be disposed within a limited cross-sectional area, even in a case where corruption of the multilayer aligned-winding coil 301 or the disabling of the aligned-winding can be avoided.